Various Improvements

Added link to demos on all appropriate pages and added a list of all demos (/demo/index.html), added link and select option value to demos (/index.html), consolidated var usage and added custom, complete mobile detection (/lib/codemirror.js), created "index.php_" to generate HTML for demo list (obviously rename it with a .php extension to view), and added a minified copy of the current JavaScript library's development version.